Pyrrolizidine alkaloid biosynthesis. Incorporation of 2-aminobutanoic acid labelled with 13C or 2H into the senecic acid portion of rosmarinine and senecionine

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Iain R. Stirling, Isabel K. A. Freer and David J. Robins


Abstract

(±)-[3,4-13C2]-2-Aminobutanoic acid 10 and (±)-[3,4-2H5]-2-aminobutanoic acid 11 are synthesized by alkylating diethyl acetamidomalonate with labelled ethyl iodide followed by acid hydrolysis. These compounds are used to obtain complete labelling patterns for the first time in a necic acid by studying the pyrrolizidine alkaloids rosmarinine 3 and senecionine 1 using NMR spectroscopy. The senecic acid portion 12 of both alkaloids shows equal incorporation of [3,4-13C2]-2-aminobutanoic acid 10 into the two C5 halves of the C10 acid consistent with formation of senecic acid via two molecules of isoleucine. After feeding [3,4-2H5]-2-aminobutanoic acid 11, retention of 2H at C-13 and C-20 of both alkaloids 13 confirms that the biosynthesis does not involve keto intermediates at these carbon atoms.


References

  1. D. J. Robins, Nat. Prod. Rep., 1984, 1, 235 RSC; 1985, 2, 213; 1986, 3, 297; 1987, 4, 577; 1989, 6, 221; 1990, 7, 377; 1991, 8, 213; 1992, 9, 313; 1993, 10, 487; 1994, 11, 613; 1995, 12, 413.
  2. A. R. Mattocks, in Chemistry and Toxicology of Pyrrolizidine Alkaloids, Academic Press, London, 1986 Search PubMed.
  3. H. A. Kelly and D. J. Robins, J. Chem. Soc., Perkin Trans. 1, 1987, 177 RSC.
  4. T. Hartmann, in Biotechnology in Agriculture and Forestry, ed. Y. P. S. Bajaj, Springer Verlag, Berlin, 1994, vol. 26, p. 339 Search PubMed.
  5. D. J. Robins, Chem. Soc. Rev., 1989, 18, 375 RSC; D. J. Robins, in The Alkaloids, Academic Press, NY, 1995, vol. 46, pp. 1–61 Search PubMed.
  6. D. H. G. Crout, N. M. Davies, E. H. Smith and D. Whitehouse, J. Chem. Soc., Perkin Trans. 1, 1972, 671 RSC.
  7. D. H. G. Crout, R. Cahill, M. V. M. Gregorio, M. B. Mitchell and U. S. Muller, J. Chem. Soc., Perkin Trans. 1, 1983, 173 RSC.
  8. D. H. G. Crout, M. V. M. Gregorio, U. S. Muller, S. Komatsubara, M. Kisumi and I. Chibata, Eur. J. Biochem., 1980, 106, 97 CAS.
  9. A. S. Chahal and M. S. Kang, J. Res. (Punjab Agric. Univ.), 1979, 16, 57 Search PubMed; R. M. Kluba, L. R. Mattick and L. R. Hacker, Am. J. Enol. Vitic., 1978, 29, 102 Search PubMed.
  10. T. Ogawa, N. Bando and K. Sasaoka, Agric. Biol. Chem., 1976, 40, 1661 CAS.
  11. M. Kasperek, Zesz. Nauk. Akad. Ekon. Poznaniu, Ser. 1, 1976, 69, 83 Search PubMed.
  12. N. F. Albertson, J. Am. Chem. Soc., 1946, 68, 452.
  13. R. Munier and M. Macheboef, Bull. Soc. Chim. Biol., 1951, 33, 846 Search PubMed.
  14. H. A. Kelly and D. J. Robins, J. Chem. Soc., Perkin Trans. 1, 1987, 2201 Search PubMed.
  15. N. J. Walton and N. J. Belshaw, Plant Cell Rep., 1988, 7, 115 CrossRef CAS; J. Walton, R. J. Robins and M. J. C. Rhodes, Plant Sci., 1988, 54, 125 CrossRef.
  16. C. G. Logie, M. R. Grue and J. R. Liddell, Phytochemistry, 1994, 37, 43 CrossRef CAS.
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